In recent years, in association with improvement of semiconductor technologies, there are enhanced demands for LED light source lamps that use solid-state light emitting elements.
The above LED light source lamps cause less power consumption, have long life, and thus greatly contribute to promotion of energy conservation. Therefore, it is expected that such LED light source lamps will explosively prevail in the future.
Here, Patent Literature 1 discloses a conventional thin LED lamp that has a built-in drive circuit.
Meanwhile, there also are great demands for good illumination where an even brightness is realized on the light-emitting surface. However, the area of a light-emitting surface of a solid-state light emitting element is smaller than that of a fluorescent tube or the like, and unevenness of the brightness on the light-emitting surface tends to occur. Therefore, in order to reduce the unevenness, in a general LED light source lamp, a diffusion film is arranged to a side toward which light is emitted from the solid-state light emitting element.
Further, in order to reduce the unevenness of the brightness on the light-emitting surface, and to make the brightness on the light-emitting surface more even, means such as a thicker diffusion film or a higher particle density in a diffusion film may be employed.